Nationally representative data on the determinants of patterns of adolescent pregnancy resolution are difficult to obtain in the United States in the absence of a uniform national abortion registration system and interlocking birth and population registers. Monitoring of repeat abortions and follow-up studies are even more difficult. It is now possible to obtain such information in Denmark, a country whose sociocultural structure and history of fertility regulation is sufficiently in advance of the United States to serve as a leading indicator of future trends. Through established linkage with the Danish Abortion Register, Birth Register, and Population Register, and by building on ongoing research, we propose to determine sociodemographic characteristics and frequency distributions associated with specific patterns of pregnancy resolution for all women in Denmark from 13 through 18 years of age and, where appropriate and possible, their male partners, with every analysis prepared by single age year cohorts. Additional analyses are proposed of adolescent women who repeat abortions or delay abortion into the second trimester, and of relationships to patterns of pregnancy resolution of (a) knowledge, attitudes, and past practices of fertility regulation; (b) influence on the decision-making process of male partners, family, peers, and health practitioners; (c) career stages; and (d) perceptions of sociocultural attitudes, values and beliefs. The proposal discusses constraints on pregnancy resolution research in the United States and advantages of conducting such research in Denmark. Previous and current related research in Denmark are described, followed by a rationale and research plan. Results are expected to fill gaps in knowledge and be generalizable for prevention and service programs. It is unlikely that similar information will soon be obtainable in the United States.